Chemicals in food packaging materials - Identification and toxicological profiling

Transcription

1 Chemicals in food packaging materials - Identification and toxicological profiling Linda Bengtström PhD

2 The Cocktail project Established in 2011 running for 4 years Largest venture in Denmark for cocktail-effects in foods (so far ) Project deliverables: Increased understanding of cocktail-effects Pragmatic tools to ultimately evaluate adverse health effects Models for calculation of cocktail-effects Survey of exposure for the Danish population

3 The Cocktail project structure Cocktail I Gathering of in vitro data Cocktail II Gathering of in vivo data Cocktail VI Emerging chemicals Cocktail III Modelling of effects Cocktail IV Modelling of exposure Cocktail V Food packaging Cocktail VII Toolbox for risk assessment

4 Cocktail V-project Toxicological profiling in silico and in vitro Unknowns in food packaging Known chemicals in food packaging with unknown effects Effect-directed analysis and analytical chemistry Bisphenol A analogues Fluorochemicals

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7 Sizing agents Adhesives ~8000 compounds Printing inks Coatings

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9 Traditional toxicology Mixture effects

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11 Raw extracts Fractions Tentative identification Quantification and identitiy confirmation In vitro testing In vitro testing Toxicological assessment Toxicity confirmed

12 Raw extracts Fractions Tentative identification Quantification and identitiy confirmation In vitro testing In vitro testing Toxicological assessment Toxicity confirmed

13 Compounds in paper Sizing agents and surface coatings Abietic acid and dehydroabietic acid Bisphenols Fluorinated compounds Dyes, printing inks and lacquers Solvent violet 8 Phtalates Adhesives Dispersants

14 Demands on extracts Two types of analyses chemistry and toxicology Solvent Low cytotoxicity Must be comprehensive High concentration Dilution prior to in vitro testing

15 Extraction of non-volatiles Boiling ethanol reflux system- Soxhlet Severe extraction Ensure enough material extracted

16 Raw extracts Fractions Tentative identification Quantification and identitiy confirmation In vitro testing In vitro testing Toxicological assessment Toxicity confirmed

17 In vitro testing- round one 20 samples in total Different properties Virgin fibre/recycled fibre Paper/paperboard/cardboard Storage conditions (temperature and duration) Fat/moist/salt content

18 In vitro testing- round one Tests: Mutagenicity ER: Endocrine disruptive effects AR: Endocrine disruptive effects AhR: Metabolism of xenobiotics Oxidative stress Metabolism

19 In vitro testing- round one

20 In vitro testing- round one Extract from pizza box in AhR assay Sandwich wrapper extract in AR assay

21 Raw extracts Fractions Tentative identification Quantification and identitiy confirmation In vitro testing In vitro testing Toxicological assessment Toxicity confirmed

22 % % % % % % % % % _067 Sm (SG, 3x3) _087 Sm (SG, 3x3) 1: Fractionation _067 Why? 0.48 Sm 0.88 (SG, 3x3) _021 Sm (SG, 3x3) 4: Reduction of compounds to be identified Decrease in matrix effects _067 Sm (SG, 3x3) ESI > e _009 Sm (SG, 3x3) Matrix component 3 MP Methyl Paraben 0 Raw extract 6.77 a) Methyl Paraben MP ESI _013 Sm (SG, 3x3) > : e4 Matrix component Fraction 6.65 b)

23 HPLC fractionation Fractions collected in 5 min intervals Fraction 1 Fraction 2 Fraction 3

24 Acidic fractionation from pizza box Alkaline fractionation from pizza box

25 Recovery of surrogates MP: Methylparaben BPA: Bisphenol A PFOA: Perfluorooctanoic acid BADGE: Bisphenol A diglycidyl ether AA: Abietic acid

26 Raw extracts Fractions Tentative identification Quantification and identitiy confirmation In vitro testing In vitro testing Toxicological assessment Toxicity confirmed

27 In vitro screening round two Fractions from sandwich wrapper

28 Raw extracts Fractions Tentative identification Quantification and identitiy confirmation In vitro testing In vitro testing Toxicological assessment Toxicity confirmed

29 Tentative identification As comprehensive as possible GC: Volatile or semi-volatile Non-polar to intermediate polar Small compounds ( Da) Thermostable Library available LC: Semi-volatile or non-volatile Larger compounds ( Da) Polar to intermediate polar No library available

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32 Cut-off Reduction of number of peaks for analysis Based on the TTC for genotoxic compounds Balance between limiting the number of compounds to be analysed the risk of removing compounds with a toxicological response GC-EI-qTOF analysis for sandwich wrapper acidic fraction 8

33 Automated data-mining Automatic peak detection and peak picking Extraction of clean peak (deconvolution) Automated mass spectral database search GC-EI-qTOF analysis for pizza box acidic fraction 9

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35 Locate molecular ion Adducts Elemental formula rules Name of rule Description Automated step /Manually inspected Restrictions of element numbers Exclusion of chemicals with unreasonable high element counts Automated step LEWIS and SENIOR Only stable ionic compounds included Automated step Nitrogen Odd monoisotopic molecular mass = even number of nitrogens* Automated step Isotope ratio Average abundance of natural and stable isotope abundances for each element Manually inspected Hydrogen/Carbon element ratio check Establishes likeliness for suggested formula (Usually 0.2 < H/C < 3.1) Manually inspected Heteroatom (N, O, P, S)/carbon element ratio check Restriction of unlikely high element ratios Manually inspected Element probability check Restriction of unlikely combinations of a high number of heteroatoms Manually inspected * Only applicable for ESI ionisation, for EI ionisation the rule is; odd monoisotopic molecular mass = odd number of nitrogens

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37 Build-up of database Lack of large commercial library in LC analysis 2100 entries of compounds reported in matrix: Intentionally added substances (IAS) Non-intentionally added substances (NIAS) List of accurate masses

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39 Parameters manually checked Realistic retention time Compared to standards of selected compounds Useful for GC Significant fragments matching

40 Parameters manually checked Matching molecular ion isotope pattern

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42 Raw extracts Fractions Tentative identification Quantification and identitiy confirmation In vitro testing In vitro testing Toxicological assessment Toxicity confirmed

43 Toxicological assessment Literature - In vivo tests - In vitro tests Structural similarities? QSAR Commercial availability

44 Toxicological assessment In total; 22 compounds tentatively identified Abietic acid and dehydroabietic acid -Naturally occurring in conifers - Sizing agent Abietic acid Dehydroabietic acid

45 Raw extracts Fractions Tentative identification Quantification and identitiy confirmation In vitro testing In vitro testing Toxicological assessment Toxicity confirmed

46 Identity confirmation and quantification Commercially available standards GC or LC separation Criteria: Rt, matching ions (MRM), ion ratio ESI > e6 ESI > e6 Abietic acid standard Unknown component in fraction nr 8

47 Raw extracts Fractions Tentative identification Quantification and identitiy confirmation In vitro testing In vitro testing Toxicological assessment Toxicity confirmed

48 Toxicological confirmation

49 Raw extracts Fractions Tentative identification Quantification and identitiy confirmation In vitro testing In vitro testing Toxicological assessment Toxicity confirmed

50 Conclusions Extraction - Able to extract compounds with different properties Fractionation - Able to separate extracted compounds into different fractions Tentative identification - Sucessful strategy by using decision tree Identity confirmation and quantification -All tentatively identified compounds in GC confirmed -6 out of 13 (43%) of tentatively identified compounds in UHPLC confirmed - 5 of these 6 confirmed had an entry in the database

51 Conclusions Effect directed analysis can be useful for Screening Identification Different toxicological effects in paper and board identified Two separation methods in tentatively identfication larger span of analytes Development of matrix matched database important for UHPLC identifcation

52 Thanks to My supervisors: Dr. Jens Højslev Petersen Dr. Kit Granby Dr. Xenia Trier The entire Cocktail-group at DTU Food Dr. Malcolm Driffield and co-workers at FERA Science Ltd.

53 Thank you for your attention!

54 Conclusions Effect directed analysis can be useful for Screening Identification Different toxicological effects in paper and board identified Two separation methods in tentatively identfication larger span of analytes Development of matrix matched database important for UHPLC identifcation